When the Olympics opened up in earnest on Saturday, you could marvel at the athletic prowess on display, cheer for your favorite country, or just enjoy the spectacle.

And in most parts of the world, you could also bet on who will win.

Las Vegas casinos will be taking bets on a handful of events this year. But as usual, international betting firms like Ladbrokes are offering odds on just about every event, from archery to yachting.

The firms stand to lose a lot of money if they post a poor line. So they are very careful about the odds they put up. The lines can give insight into who the most likely winners are in every event, and just how likely they are to win.

You probably expect the U.S. women’s basketball team to win the gold medal. If it happens, it won’t make you rich: the odds are 1-10, meaning you put up $10 for a chance to win just $1 of the bookmaker’s money. The U.S. men are even bigger favorites, at 1-12. The other Dream Team at these games is the Russian women’s synchronized swimming team, at 1-10.

In rowing, don’t expect exciting competition in the pair events: New Zealand is 1-33 in the men’s and Britain 1-12 in the women’s. China should dominate the synchronized diving. Its four teams are 1-5, 1-6, 1-16 and 1-16. Australia should win the women’s 4x100 freestyle relay (1-7) and the United States should win the 4x200 (1-10).

And for every favorite there is a massive underdog. There are only 12 teams in basketball, but the China and Venezuela men and the Senegal and Japan women are all 1,000-1. Leicester won the English Premier League at 5,000-1 this year, so it’s not impossible, right?

Wonder how the big-name Americans will do? Simone Biles is 2-5 to win the gymnastics all-around, and Ashton Eaton 1-10 in the decathlon. Michael Phelps is favored to win the 200 individual medley and 100 butterfly, but considered to be in a tight three-way race in the 200 butterfly with Laszlo Cseh of Hungary and Chad le Clos of South Africa.

But the biggest American favorite is Katie Ledecky. She is 7-10 to win the 200-meter freestyle, but a mind-boggling 1-50 to win at 400 and 800 meters. Sure things don’t get much surer.

If sports betting is legal in your jurisdiction, you can start right away. On Saturday, the first gold medal will be awarded in women’s 10-meter air rifle. Yi Siling of China is the favorite; Jennifer McIntosh of Britain is 100-1.

So where should you put your money? Here’s a look at some contenders who seem like savvy wagers.

One reliable betting strategy is to go against the biggest names, who casual fans might overbet. You’ve probably heard of Usain Bolt. He is not quite as fast as he used to be, and the American Justin Gatlin may be a good bet, at 2-1, to win the 100-meter dash. Similarly, Geoffrey Kamworor Kipsang of Kenya could upset Mo Farah of Britain in the 10,000 meters at 6-1. And for a flyer on an American long-shot, try Shalane Flanagan at 25-1 in the women’s marathon.

Some swimmers flying under the radar include Abbey Weitzeil of the United States in the women’s 50 freestyle (33-1), Mireia Belmonte of Spain in the women’s 400 individual medley (16-1), and Kevin Cordes in the 200 breaststroke (11-1).

Pedro Solberg and Evandro are Brazilian hopes in beach volleyball at 5-1, a better price than their countrymen, the favored Alison and Bruno. In indoor volleyball the Chinese women (9-2) and Polish men (9-1) could surprise.

And to maybe make some money, but at least win points for in-depth knowledge of the most obscure sports, try Servet Tazegul of Turkey, the world champion but only the 3-1 favorite in 68-kilogram men’s taekwondo.